"Last Kingdom is a set of books that . . . is neither philosophical argumentation nor little disparate, scholarly essays, nor novelistic narrative; gradually, for me, all genres have fallen away."   So writes Pascal Quignard of his monumental book series, Last Kingdom. In the latest volume, The Fount of Time, he focuses on the paradoxically immediate presence in our lives of the deepest, most distant past. He explores this subject through a multitude of mediums: fragments of autobiography; curious folktales; literary snippets; historical anecdotes both classical and modern; ruminations on biology, archaeology, and linguistics. Using all of these forms, he confronts dimensions of human experience which, though customarily conveyed in legend, myth, and dreams, run somehow beneath the everyday world and yet are part of our most tangible reality.   To enter Quignard's horizonless time-space is to embrace a rich vision in which the totality of human history and culture is placed disconcertingly on a single footing. In The Fount of Time we are able to glimpse--whether through obscure cultural detail or unusual anecdote--"another world beneath the world."